1. Field of the Invention
The present invention relates to an optical payload configured to be carried by an Unmanned Airborne Vehicle (UAV) conforming to Class II UAV standards. In particular, the payload includes two or more video cameras and electrical systems suitable for combining video images from two cameras into a single network packeted data stream. A primary video camera includes a folded telescope and a folded cryocooler to reduce a volume footprint of the optical payload. A laser rangefinder and laser target designator share a large aperture telescopic lens system to further reduce a volume footprint of the optical payload. A hollow cylindrical yoke assembly houses circular PC boards to further reduce a volume footprint of the optical payload.
2. Description of the Related Art
Optical payloads for airborne reconnaissance are described in the patent literature. One example system is disclosed in U.S. Pat. No. 5,005,083 by Grage et al. which describes a dual channel camera having wide and narrow fields of view and electrical systems suitable for tracking a target and for combining full image information from both fields of view in a single picture using a mixing device. However, Grage et al. is silent as to whether the two cameras have different spectral ranges, as to the specific camera or pointing platform designs, or as to whether the system includes an incorporated laser range finder or laser target designator.
Another optical payload system is disclosed in U.S. Pat. No. 6,410,987 by O'Neil which describes a video imaging system that includes wide and narrow field of view lens systems each forming an image of a target area onto the same infrared sensitive focal plane array. The system includes a movable mirror disposed to direct either the wide field of view or the narrow field image of the target area onto the infrared sensitive focal plane array, but not both. The infrared sensor is a two-color sensor having two regions with a first region sensitive to a first infrared wavelength range and a second region sensitive to a second infrared wavelength range. The system includes a dichroic beam splitter disposed between the movable mirror and the two-color focal plane array for dividing the image of the target area into two color images. The dichroic beam splitter splits the image of the target image area into two color images and directs a first color image onto the first focal plane array region sensitive to the first infrared wavelength range and directs the second color image onto the second focal plane array region sensitive to the second infrared wavelength range. However, O'Neil does not teach an optical payload that utilizes a plurality of focal plane arrays with different spectral sensitivity ranges or an optical payload that is capable of rendering and simultaneously displaying video images of the target area over two different fields of view and over two different spectral ranges.
One example of an optical payload that incorporates a laser rangefinder and a laser target designator and uses a single large aperture optical system to perform multiple tasks is described in U.S. Pat. No. 6,903,343 by Amon et al. which describes a payload having a wide field of view small aperture optical system and a narrow field of view large aperture optical system wherein the large aperture optical system is used to collect energy from a target area to provide a narrow field of view image of a target area focused on a first detector, and an image of a laser designator spot formed on the target area also focused onto a first detector. However, the Amon et al. disclosure does not teach incorporating laser range finder and laser target designator emitters into the optical payload.
There is a need to reduce the size and weight of camera systems used on Unmanned Airborne Vehicle (UAV). More generally, there is a need to further integrate optical payloads to provide increased functionality, reduced weight and improved aerodynamic performance without sacrificing image quality or decreasing the useful range of the device. It is also useful to allow a user to view two images simultaneously such as a low magnification image of the target area to provide situational awareness and a high magnification image of a selected target within the target area. Moreover UAV payloads may require a visible camera to provide color day image in daylight so that target areas are more recognizable to a remote operator. This is not usually required in a manned aircraft since the aviators are able to see the target area in daylight. The present invention remedies the problems encountered in the prior art.